Technical Field
Embodiments of the present disclosure relate to a control apparatus for an internal combustion engine, and more particularly to a control apparatus for an internal combustion engine that is suitable as an apparatus for controlling an internal combustion engine that includes an in-cylinder pressure sensor.
Background Art
In Japanese Patent Laid-Open No. 2008-069713, a combustion control apparatus for an internal combustion engine that includes an in-cylinder pressure sensor is disclosed. In the combustion control apparatus, data of mass fraction burned that is synchronized with a crank angle is calculated using an in-cylinder pressure sensor and a crank angle sensor, and an actual combustion start point and a combustion center are calculated based on the data. In addition, if a difference obtained by subtracting the actual combustion start point from the combustion center exceeds an upper limit, the combustion control apparatus determines that combustion has deteriorated, and implements a countermeasure for improving combustion, such as increasing the fuel injection amount. Note that, in Japanese Patent Laid-Open No. 2008-069713, as one example, an appropriate value in a period in which mass fraction burned is from 10 to 30 percent is used as the aforementioned actual combustion start point that is a crank angle at which combustion is actually started in a cylinder, and, for example, an appropriate value in a period in which mass fraction burned is from 40 to 60 percent is used as the combustion center.
Following is a list of patent documents which may be related to the present disclosure.
[Patent Document 1]
Japanese Patent Laid-Open No. 2008-069713
[Patent Document 2]
Japanese Patent Laid-Open No. 2014-025380
[Patent Document 3]
Japanese Patent Laid-Open No. 2006-169996
[Patent Document 4]
Japanese Patent Laid-Open No. 2012-077729
[Patent Document 5]
Japanese Patent Laid-Open No. 2004-353531